Enhancing Salt Tolerance of Cucumber Using Grafting and Some Bioregulators

Abstract

Experiment was conducted in a greenhouse in El-Salehea Al-Gadeda, Sharqia Governorate during the two successive seasons of 2008/ 2009 and 2009/2010 to investigate the effect of grafting technique, bioregulators; salicylic acid (SA) at 0.5 & 1 mM, fulvic acid (FA) at 150 & 300 ppm and sea weed extract (SWE) at 2.5 & 5% in addition to osmoregulators (compatible solute); glycine betaine (GB) at 2.5 & 5 mM in improving salt tolerant of grafted cucumber plants (Cucumis sativus L. cv. falcon, Hybrid F1) under saline conditions. Grafting of cucumber on salt tolerance rootstock (Shintosa supreme pumpkin) significantly increased growth and fruits yield, relative water content (RWC) and antioxidant enzymes activity. Furthermore, grafting significantly increased chlorophyll, carotenoid, proline and total soluble protein concentrations. Grafting reduced membrane permeability and malondialdehyde (MDA) concentration in leaves of cucumber plants under salt stress conditions. Foliar application of SWE, SA, FA and GB significantly improved growth and yield parameters, and biochemical contents of grafted cucumber plants compared to untreated grafted plants under salt conditions. The superiority was due to SWE (5%) followed by FA (300 ppm) then GB (5 mM).